The most common headrails for venetian blinds, pleated shades, cellular shades and roman shades are made from a U-shaped channel which is mounted in a window opening by attachment either to the face of the window frame, or by an end mount to the inner walls of the window casing, or by an overhead mount to the upper wall of the casing or to the ceiling adjacent to the window. Almost always the headrail is mounted in any one of these three ways by two or more brackets. One type of bracket is cup-shaped and fits onto the end of the headrail. Another type of bracket is L-shaped and attaches to the top of the headrail. These brackets have screw holes in them positioned for each of the mounting connections. Most brackets are about two inches in width. The installer determines how many brackets to use and where to place the brackets relative to the headrail. Often installers use more brackets than are necessary or place them in the wrong positions. The forces that act on a window blind headrail are not equally distributed across the headrail. More force is applied to the end of the headrail at which the lift cord exits from the headrail. On occasion an installer will not place a bracket in the region of the headrail where the forces are greatest resulting in the headrail coming loose or falling. Sometimes the headrail is slightly smaller than the window opening in which it is mounted. When that occurs the headrail can move laterally because some of the brackets being used today do not prevent lateral movement of the headrail very well. Repeated lateral movements cause the shade to be off centered on the window and could result in damage to the headrail, the brackets and even the shade. Consequently, there is a need for a mounting system for window covering headrails that uses the right number of brackets, correctly positioned, for the forces that will act on the headrail. There is also a need for a window covering mounting system that will restrain the headrail from lateral movement. Brackets in use today are unattractive from outside the window especially where porches or patios are adjacent to the windows. Thus, there is a need for an attractive bracketing system.
The usual practice in selecting a window covering having a headrail is to measure the opening of the window and select a standard size headrail having a length that will fit the measured opening, cut down a standard size headrail to fit the window, or custom make a headrail to measure. Sometimes the measurements are made by the homeowner and sometimes an installer measures the window. Many homeowners fear that the measurements they make will be incorrect. When that does occur, the blind which has been custom made according to the measurements given by the homeowner must be replaced or cut down to the proper size. This results in additional expense to the seller as well as delay in installation. Installers also sometimes make incorrect measurements and the same problems result. There is a need for a system that will assure correct measurements are made, thereby eliminating the situation where products are sized incorrectly and an installer or homeowner attempts to install a window covering that does not fit the window opening.